Re: [HACKERS] Question about todo item

[Tom Lane]

Bruce Momjian <[EMAIL PROTECTED]> writes:
> I keep bugging Jan about it, since pre-7.1 and no one has come up with
> an idea.

Well, if you want an idea:

        BEGIN;

        SELECT open_toast_object(toastable_column) FROM tab WHERE ...;

        -- app checks that it got exactly one result back

        -- app lo_reads and/or lo_writes using ID returned by SELECT

        END;

Implementation is left as an exercise for the reader ;-).

Offhand this seems like it would be doable for a column-value that
was actually moved out-of-line by TOAST, since the open_toast_object
function could see and return the TOAST pointer, and then the read/
write operations just hack on rows in pg_largeobject.  The hard part
is how to provide equivalent functionality (transparent to the client
of course) when the particular value you select has *not* been moved
out-of-line.  Ideas anyone?

                        regards, tom lane

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